我试图通过在X轴上传递时间值并在Y轴上传递表示货币金额的整数值来使用danielgindi/ios-charts library创建折线图。
时间值，因为它在有限的时间间隔内，因为我试图将其限制为7个元素，所以我首先将其转换为unix并检查其中的一个元素是最旧的，然后从较新的元素中替换较旧的元素，因此得到NSNumbers数组。
这是我的代码和数组数据：
- (void)addChartWithArray:(NSArray *)dataArray{
NSMutableArray *xVals = [[NSMutableArray alloc] init];
NSMutableArray *yVals = [[NSMutableArray alloc] init];
int maxNumberOfValuesInGraph;
if(dataArray.count >= 7){
maxNumberOfValuesInGraph = (int)dataArray.count - 7;
}else{
maxNumberOfValuesInGraph = 0;
}
for (int cout = maxNumberOfValuesInGraph; cout < dataArray.count; cout++){
TRTargetEstimation *targetEstimation = [dataArray objectAtIndex: cout];
[xVals addObject:[targetEstimation dateCreated]];
}
xVals = [self calculateTimeValues: xVals];
int secondCounter = 0;
for (int cout = maxNumberOfValuesInGraph; cout < dataArray.count; cout++) {
TRTargetEstimation *targetEstimation = [dataArray objectAtIndex: cout];
[yVals addObject:[[ChartDataEntry alloc] initWithValue:[targetEstimation.estimationValue floatValue] xIndex:secondCounter]];
secondCounter++;
}
LineChartDataSet *set1 = [[LineChartDataSet alloc] initWithYVals:yVals label:@"DataSet 1"];
set1.lineWidth = 2.f;
set1.circleRadius = 6.0;
[set1 setColor: [UIColor orangeColor]];
[set1 setCircleColor:[UIColor orangeColor]];
set1.highlightColor = [UIColor orangeColor];
set1.drawValuesEnabled = YES;
LineChartData *data = [[LineChartData alloc] initWithXVals:xVals dataSet:set1];
[data setValueFont:[UIFont fontWithName:@"HelveticaNeue-Light" size:7.f]];
self.lineChartView.minOffset = 0;
self.lineChartView.delegate = self;
self.lineChartView.backgroundColor = [UIColor clearColor];
self.lineChartView.descriptionText = @"";
self.lineChartView.noDataTextDescription = @"No history available.";
self.lineChartView.drawGridBackgroundEnabled = NO;
self.lineChartView.dragEnabled = NO;
[self.lineChartView setScaleEnabled:NO];
self.lineChartView.pinchZoomEnabled = NO;
[self.lineChartView setViewPortOffsetsWithLeft:10.0 top:0.0 right:10.0 bottom:0.0];
self.lineChartView.legend.enabled = NO;
self.lineChartView.leftAxis.enabled = NO;
self.lineChartView.rightAxis.enabled = NO;
self.lineChartView.xAxis.enabled = NO;
self.lineChartView.data = data;
self.lineChartView.hidden = YES;
self.leftLineView.hidden = YES;
self.bottomLineView.hidden = YES;
}
- (NSMutableArray *)calculateTimeValues:(NSMutableArray *)passedArray {
NSMutableArray *returnedArray = [[NSMutableArray alloc] init];
for (int count = 0; count < passedArray.count; count++) {
NSDate *date = [TRUtils getDateOutOfString:[passedArray objectAtIndex:count]
andDateFormat:@"yyyy-MM-dd HH:mm:ss"];
[returnedArray addObject:[NSNumber numberWithInt:[TRUtils getUNIXTimeFromDate:date]]];
}
[returnedArray sortUsingDescriptors:[NSArray arrayWithObject:[NSSortDescriptor sortDescriptorWithKey:@"self" ascending:YES]]];
int minValue = [[returnedArray firstObject] intValue];
for (int count = 0; count < passedArray.count; count++) {
[returnedArray replaceObjectAtIndex:count
withObject:[NSString stringWithFormat:@"%d",[[returnedArray objectAtIndex:count] intValue] - minValue]];
}
return returnedArray;
}
这是我的辅助方法：
+ (NSDate *)getDateOutOfString:(NSString *)passedString andDateFormat:(NSString *)dateFormat{
NSString *dateString = passedString;
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:dateFormat];
NSDate *dateFromString = [[NSDate alloc] init];
dateFromString = [dateFormatter dateFromString:dateString];
return dateFromString;
}
+ (int)getUNIXTimeFromDate:(NSDate *) datePassed{
return (int)[datePassed timeIntervalSince1970];
}
和xVals数据是：
<__NSArrayM 0x7fca4b775dd0>(
0,
213,
298,
435,
524,
591,
664
)
yVals数组是：
[234234,
123123,
2223355,
22222222,
2342,
121212,
121212]
该图显示为：
现在，Y轴看起来像预期的那样，但是Y轴不正确，因为点之间的间距相等，对我做错了有什么想法吗？
我已经尝试更改下一行：
[yVals addObject:[[ChartDataEntry alloc] initWithValue:[targetEstimation.estimationValue floatValue] xIndex:secondCounter]];
通过提供一个不同的xIndex，但是该图形在屏幕上完全停止显示。
预先感谢所有建设性的答案:)
最佳答案
我假设您的意思是“ X轴不正确，因为点之间的间距相等，对我做错的事情有任何想法吗？”
这是设计使然。要解决此问题，您需要为x轴插入中间日期值，但不为规范xIndex插入任何数据条目。这已经在github页面上问过了。
您必须为[self hasDataAtIndex:cout]编写自己的逻辑
for (int cout = maxNumberOfValuesInGraph; cout < dataArray.count; cout++){
TRTargetEstimation *targetEstimation = [dataArray objectAtIndex: cout];
[xVals addObject:[targetEstimation dateCreated]];
if ([self hasDataAtIndex:cout]) {
[yVals addObject:[[ChartDataEntry alloc] initWithValue:[targetEstimation.estimationValue floatValue] xIndex:cout]];
}
}